This invention relates to the field of kinetic energy projectiles which employ long rod cores as penetrators, used for example to pierce armor upon impact. More particularly, the invention relates to a strengthened penetrator rod, by varying the materials and construction thereof.
The quest for ever stronger penetrators, to defeat ever thicker and harder enemy armor, is a continuous one. One conventional type is made of tungsten. The typical method for fabricating penetrators from tungsten involves the use of tungsten powder metal, which is mixed with other metal powders, compacted to shape, sintered, and processed into penetrators. One of the limiting factors for penetrator usage is the inability to obtain high enough metallurgical properties (strength, toughness, etc.) with the penetrator materials currently available. Additional materials used for penetrators include depleted uranium (DU) and liquid phase sintered (LPS) tungsten metals and alloy variations thereof. Another aspect includes composite additions to the metal long rod, such as fiber reinforcement. With fiber reinforcement, an appropriate fiber array is encapsulated by a plastic or metal matrix, producing a composite material with improved properties. The fibers must not dissolve in the encapsulating medium; they should remain intact and be wetted and encased by the matrix medium.
Composite studies with long rod projectiles have included straight fibers, chopped fibers, and rolled sheet; this last item consists of a thin sheet of material rolled into a helix before being encapsulated. These long rods have improved tensile properties which helps the projectile to resist both tensile stresses during launch and bending stresses when penetrating multilayered oblique armor targets. Unfortunately, because of the open endedness of the fibers or sheet at the impact end of the penetrator, the front end of the composite long rod splays open or splits apart under the compressive forces generated during ballistic impact; this significantly reduces penetration ability.
Any improvement therefore, of the strength, toughness, etc. of long rod penetrators in general and of fiber reinforced rods in particular, would be seen as a great advance in this art.